This invention is a posterior chamber capsular lens implant and a method and apparatus for the implantation of the lens within the posterior chamber of the eye.
Surgical extraction of a cataract impaired lens of the human eye is a medical procedure under much research at the present time. Complete visual performance of the eye is the objective sought from such a procedure. To achieve this objective, the natural lens can be removed and an artificial lens then implanted within the eye. Due to the structure of the eye, the implant must be located either in the eye's anterior chamber or in its posterior chamber. Posterior chamber lens implants provide the most natural and effective substitute for the removed original lens of the eye.
Prior art for posterior chamber lenses reveal major disadvantages. One of such disadvantages is the requirement that sutures be fixed inside the eye in order to centralize the location of the lens implant. Another is placement of the lens implant in front of the capsular bag resulting in impact against the vascular tissues of the ciliary body.
Examples of the prior art posterior lenses are few. The Pearce posterior chamber lens is a lens with three haptics extending from the len's edge. The lens is then sutured into its position within the posterior chamber. The Harris lens is similar to the Pearce lens with primary variance in the number of haptics, having four instead of three.
A lens which does not require the use of fixating permanent sutures, and is a posterior chamber lens implant, is the Shearing lens. A Shearing lens utilizes two opposing incomplete loops attached to the lens at one end and free at the other end to give each loop compressibility and to centralize the lens in front of the capsular bag of the eye. The loops stabilize the centralized location of the lens once it is implanted, but given the structure of the Shearing loops, this stabilization can occur by impacting against the ciliary body. It is possible that the free ends of the len's loops could cause harm to the interior of the eye. Such harm could eliminate the Shearing lens' advantages over posterior chamber lens implants which require the use of sutures to centralize their location.
Thus, the continued requirement of sutures and the location of the implant's impact within the eye necessitated further research for a more effective and safer substitute for the removed natural lens of the human eye.
Accordingly, there exists a need for a sutureless lens implant for the posterior chamber capsule which is self-centering, which can be safely implanted and which remains in position within the capsular bag. The instant invention is directed to that need as it provides a lens, and a method and apparatus for implanting such a lens.